The Skin Factor
While some scientists and physicians studied how the body worked and how to persuade
it to fend off diseases, others puzzled over how to insert medicines and
other substances such as vaccines.
Having an effective vaccine that could produce sufficient immunity was useless
without being able to get it into the body in a harmless way. Edward Jenner
used a lancet and scratched two lines on James Phipps’s arm. Fifty
years after Jenner, the hypodermic syringe became available. In 1885, scientist
Louis Pasteur used one to vaccinate a young boy who had been bitten by a
mad dog and was sure to die of rabies—the
boy lived, and immunization took
another giant step forward.

As more immunizing agents became available, people saw the benefit
of immunizing large groups, such as soldiers. During World War I, they
were vaccinated against diphtheria; during World War II, typhus and
tetanus.

The Future Has a Past
In the 19th century, use of the hypodermic syringe was limited by dependence
on large needles that could rust or snap in two, glass barrels that cracked,
and tips that leaked. Before disposable needles in the 1960s, needles needed
to be sharpened and sterilized. Since then, technological improvements include
sharper, thinner needles and safety features. Still, more than a few people
would like to avoid a shot in the arm.

Hypodermic injection remains the most common method of getting through
the skin. But it is not the only technology for immunization. Engineers
and scientists continue to search for alternative routes into the body,
such as through the moth or nose. And continuing to solve the technological
problems is critical for countries in which illness and death rates
are high as a result of measles, maternal tetanus, and other preventable
diseases.

A successful instrument or system must get the vaccine into the body
with minimal disruption, and be cost-effective for use with billions
of people. And perhaps the most important problem today—preventing
reuse of syringes to avoid cross-contamination—was not even imagined
in the 19th century.

These devices represent different approaches to immunization Hugh
Talman, photographer